This invention relates to a workpiece stacker, and more particularly to a workpiece stacker adapted to stack workpieces as sewed above a panel.
As is well known to those skilled in the art, there have in the past been proposed workpiece stackers of the type shown in FIG. 5 and illustrated in Japanese Laid Open Utility Model Publication No. Hei 1-99376. In such earlier stacker systems, a first workpiece clamping member 2 and a workpiece throw-over member 3 beneath a sewing machine were adapted to have forward ends 2b, 3b thereof rotated about pivot points 2a, 3a. A bed or panel 6 is mounted on a pipe or rod 5 which is disposed downwardly of a working table 4 and is supported by a machine frame 7. A second fabric clamping member 8 is provided downwardly of the working table 4 to have its forward end 8b rotated about a pivot point 8a. Rotation of the forward end 8b of the workpiece clamping member 8 is in association with the first workpiece.
The conventional workpiece stacker arranged as aforementioned is designed so that the first workpiece clamping member is rotated about the pivot point 2a to abut or press a marginal edge of a workpiece 9 suspended from the bed of the sewing machine 1 against the rod 5 as shown by a dotted line in FIG. 5.
In association with the rotation of the first workpiece clamping member 2, the second workpiece clamping member 8 is rotated upwardly to move the forward end 8b of the second workpiece clamping member 8 to the position shown by a dotted line in FIG. 5. The workpiece throw-over member 3 is caused to rotate its forward end 3b about the pivot point 3a to urge the intermediate or medium portion of the workpiece 9 to turn over the upper end of the workpiece 9 on the rod 5. The forward end 3b of the workpiece throw-over member 9 is moved in turn as shown by a dotted line above a stacker 6 so that the workpieces 9 are stacked on the rod 5 and the stacker 6. The first workpiece clamping member 2 and the throw-over member 3 are then returned to initial positions. As the first workpiece clamping member 2 is rotated, the second workpiece clamping member 8 is returned to its position as shown in solid line to urge the stacked workpieces 9.
As mentioned above, in the conventional workpiece stacker of FIG. 5, the rod 5 is rigidly mounted on the underside of the working table 4 so that the number of the workpieces 9 to be stacked is determined by the distance between the working table 4 and the rod 5, and the distance between the rod 5 and the first workpiece clamping member 2 and the workpiece throwover member 3. To increase the number of the workpieces 9 to be stacked, the workpiece draping rod or bar 5 is mounted in a lower position or kept away form the clamping member 2 and the throw-over member 3. As a resultant draw-back, the workpiece, if it is of a short length, is hung from the sewing machine 1 and is neither draped over nor stacked properly.